New technology converts tannery waste into green soles

India

Published: 24 June, 2015

A group of scientists from the Council of Scientific and Industrial Research (CSIR) and Central Leather Research Institute (CLRI) in India have developed a new means of converting liquid waste from tanneries into a major compound in shoe manufacturing.

Fleshings and fat have been converted into activated carbon using the CSIR system. Usually disposed in landfills leading to contamination of groundwater, fleshing has become a viable alternative to the carcinogenic carbon black widely used in making soles of leather shoes. This activated carbon not only adds colour but is also used as a reinforcing material in soles. Cost effective and lightweight, the compound reinforces strength whilst remaining flexible and abrasive resistant.

This technology is a result of the Zero Emission Research Initiatives for Solid Waste, a network project from CSIR. Unlike the conventional activated carbon which does not contain cross-linking agents such as calcium oxide and, therefore, cannot be used as filler in rubber manufacturing, the activated carbon converted from fleshing waste does contains calcium and can be used effectively as a filler in rubber manufacturing.

According to Chief Scientist, J Raghava Rao, the activated carbon matches the properties of conventional rubber soles. It is lightweight and leaves no imprint on carpets, one of the drawbacks in conventional soles. Furthermore, it doesn’t have the carcinogenic properties of carbon black and is less expensive than silica, which is which also fails to give the intended colour tone. Patented by CLRI, this new technology is targeted at environmentally conscious companies that aim to reduce their carbon footprint